"You all know about my interest in digital art and where these tools might take our culture. Here is an amazing performance by Hatsune Miku, a virtual pop singer in Japan that was created thru internet collaboration among song writers, manga artists, musicians and, of course, mass marketing experts. I find it amazingly heartwarming how this whole phenomenon has been embraced by Japanese youth culture. If this doesn't get you to thinking about what we humans are made of, I don't know what will. You gotta love the Japanese.

"Hatsune Miku is a 16-year-old girl with long green pigtails and a voice with a range no human could ever hope to match.
She is a virtual singer with a computer-synthesized voice, a work by creators who met on the Internet.
Many of the songs she sang have proven to be so appealing that the music industry cannot ignore her. She has developed into a singer with a large worldwide following."

We see in this YouTube video a "live" performance. Indeed, a Hatsune Miku animation with voice was projected onto a large screen before a wildly
enthusiastic live audience (live musicians too), and then the entire project was video-recorded for whatever distribution was intended, as on YouTube.
So in a sense the performance is real but Hatsune Miko and her voice are not. Spectacular, or is this just excessive digital technique? About 3-minute playing time.